The present invention relates to fire protective intumescent curable compositions.
Over the years, intumescent compositions have been utilized for a variety of structural applications including columns, I-beams, girders, bulk-heads and a variety of other structural building components. A very important requirement of these compositions is the ability to uniformly form a carbonaceous char during a fire which will adhere to the substrate without cracking. In addition, it is very important that the unburned composition adhere well to the substrate without cracking in order to protect the underlying substrate from damage brought about by climatic exposure and also for the composition to be in good condition should a fire occur. A composition which is already cracked in the unburned state provides a diminished level of protection to the underlying substrate once it burns and forms a char since there is a greater likelihood that the char formed during a fire will fall from the substrate leaving it unprotected.
A major cause of cracking in the unburned state is the climatic conditions to which the composition is exposed. For example, dramatic temperature shifts from very hot to very cold within a short period of time such as over the course of a day contribute to stresses within the composition which may lead to cracking.
There is a need, therefore, for a curable intumescent composition which is capable of adhering to a substrate without cracking in the unburned state, even when exposed to extreme changes in temperature and weather conditions; and in addition which is capable of intumescing to form a uniform carbonaceous char upon exposure to heat or flame thereby protecting the underlying substrate from the structural damage which may be brought about by a fire.